Let us say for instance you want to monitor the latency between the border routers to the dslams.
You can use our WAN RTT Monitor add-on to monitor the latency of end routers.
We use Cisco IP SLA to monitor the latency and raise alerts based on the thresholds you configure in OpManager. To know more about Cisco IP SLA, look at the link given below: https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/ipsla/configuration/15-mt/sla-15-mt-book/sla_overview-0.html
The WAN RTT (Round Trip Time) monitor will help you,